JoC #15: Object interaction (first encounter)

      The pure and simple truth is rarely pure and never simple.
            — Oscar Wilde

Today a long, and quite full episode. We encounter various very important concepts for the first time: local variables, class types and object interaction.

If you have questions left after watching this – don’t worry. We will look at all of this again in more detail in future episodes. And you can use the comments below to ask your questions (or make any other comments).

By the way, I just noticed I made a mistake. (Yes, that does happen!) There is a bug in the program that I’m writing in this episode. Can you spot it?

Download video

Concepts discussedvariable, field, local variable, assignment, class type, object interaction, external method call


JoC #3: Classes and objects

    If a man writes a book, let him set down only what he knows.
    I have guesses enough of my own.

          — Goethe

Alright, now it finally starts getting interesting! After the previous talk about installation, now we’re getting started actually doing stuff.

Watch this episode to get the first feel for working with Greenfoot, and see what classes and objects are all about.

Download video

Concepts discussed: class, object, method, instance, return value, return type, void, int, boolean

And, as I said in the video: Follow @JoyOfCode on Twitter to get updates when new episodes are posted.

Scenario download for this episode: hedgehogs.zip      (save and unzip before opening)